Power bank



FIG. 1 is a perspective view of the power bank showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a back view thereof;

FIG. 4 is a left view thereof;

FIG. 5 is a right view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

The broken lines shown in the drawings are included for the purpose of illustrating unclaimed portions of the power bank and form no part of the claimed design. 

CLAIM The ornamental design for a power bank, as shown and described. 